The skin is the largest organ in the body and serves as a protective barrier from the external environment, impeding the entry of microorganisms, absorption of radiation and loss of water. The skin is composed of three layers differing in their cell types and special functions; an overlaying epithelial layer (epidermis), an underlying connective tissue matrix (dermis) and adipose tissue (hypodermis). Skin roughness is one of the main criteria for assessing the health status of human skin. Changes in ski surface roughness, which give the skin the effect of having wrinkles, may occur due to congenital keratinization disturbances, environmental and job related skin irritations, infectious skin diseases and age related defects. Some skin disorders are related to a specific mineral shortage. About 4-5% of the human body is made up of minerals. It is assumed that specific ions from minerals play an important role in healthy skin metabolism. There are indications that Mg.sup.+2 is a co factor for phosphate transferring enzymes and participates in cAMP regulation. Ca.sup.+2 is thought to induce lamellar body secretion and regulate cell membrane permeability and K.sup.+ is known to enhance CO.sup.2 transport. In some in vitro and in vivo tests magnesium bromide, magnesium chloride, and potassium bromide (all selected Dead Sea salts) exhibited inhibition of skin cell proliferation after dermal application, making them possibly applicable for care of psoriasis (As discussed by Shani, J., Sulliman, A., Katzir, I, and Brener, S. in J. Eur. Acad. Dermratol. Venereol. (1995) 4, 267-272 and by Levi-Shaffer, F., Shani, J., Politi, Y., Rubinichik, E. and Brener, S. in Pharmacology (1996) 52, 321-328). Minerals are capable of restoring moisture due to their hygroscopic characteristics. Minerals, if absorbed into skin cells, may enhance intracellular water capacity. Minerals may be absorbed into the skin from brine, from a bath with dissolved salts, or from application of a mineral rich preparation.
The Dead Sea is the richest natural mineral source in the world, with a concentration of 32% (w/v) dissolved minerals and a unique composition. The main elements found in Dead Sea water are chlorine, magnesium, sodium, calcium, potassium and bromine. For example, the concentration of chlorine in the Dead Sea is 224900 mg/l as opposed to 22900 in the Mediterranean and 19000 in typical ocean water. Magnesium is 44000 mg/l in the Dead Sea as opposed to 1490 and 1350 in the Mediterranean and ocean, respectively. Sodium is 40100 mg/l in the Dead Sea as opposed to 12700 and 10500 in the Mediterranean and ocean, respectively. Calcium is 17200 mg/l in the Dead Sea as opposed to 470 and 400 in the Mediterranean and ocean, respectively. Potassium is 7650 mg/l in the Dead Sea as opposed to 470 and 390 in the Mediterranean and ocean, respectively and bromine is 5300 mg/l in the Dead Sea as opposed to 76 and 65 in the Mediterranean and ocean, respectively.
It has been acknowledged for years that these elements are beneficial for human skin and health. Minerals are alleged to relieve diseases such as rheumatism, acne, eczema and psoriasis (Ma'or, Z., Magdassi, S., Effron, D., Yehuda, S Isr. J. Med. Sci. 32 (suppl 3), 28-35 (1996)). Algae and plants are an especially rich natural source of vitamins and minerals. Algae grown in mineral rich water and in severe environmental conditions are capable of concentrating large amounts of these substances. Uses for algae in food and in external dermal applications, are known, and the use of marine algae in spas is prevalent. There is a large world market for cosmetic compositions containing minerals. However, the benefits of minerals in Dead Sea water are limited due to the natural high concentration of divalent ions and the very high ionic strength of the Dead Sea water. Another drawback of the mineral rich cosmetics marketed today is the fact that the skin itself presents a natural barrier to the penetration of minerals. These drawbacks have a negative effect on the formation and stability of compositions.
The present invention relates to a composition for skin care, especially for care of changes in skin surface roughness (wrinkles), for retaining skin moisture and for relieving skin related diseases such as acne, eczema and psoriasis. The composition of the present invention combines Dead Sea water solutions with algae and plant extracts, achieving a highly mineral rich composition and utilizing the algae bio mass as a carrier of minerals and their possibly controlled release, thereby overcoming the drawbacks of the compositions marketed today and presenting a superior composition for cosmetic use and skin care and protection.